Like most trombonists, I suffer from what can only be described as 'multiple trombone acquisition syndrome'. In other words, one trombone is never enough and so I have several to cover every eventuality! Here are my current instruments:
Boosey & Hawkes Imperial Bass Trombone (single plug)
Unnamed Bb Sousaphone
Unnamed Eb Sousaphone (body)
Rocket Electric Upright Bass (EUB)
Rosehill Instruments Eb Tuba
Hawkes and Son G Trombone
Jupiter Soprano Trombone
This is my most frequently used trombone. It's a 1980's instrument I acquired via eBay. It looks slightly tatty, although I have spruced it up by adding a 'brushed brass' effect to the slide, but still plays well and the slide is pretty good. I use a Vincent Bach 5G mouthpiece (I think like Dennis Wick did on the Star Wars soundtracks with his 88H!)
My most fun trombone, great for Christmas carols. This always attracts attention, and the kids love it! Plays surprisingly well, not dissimilarly to the 3B. The slide can be a bit sticky, but it's incredibly light and comfortable. The mouthpiece supplied with the instrument is usable but I added a Kelly 12C in orange to match.
This is the instrument I use for jazz gigs. I use a Rath S11 Model M.N. (Mark Nightingale) mouthpiece. I have fitted a Neotech trombone grip to make it more comfortable to hold due to tendonitis in my left elbow.
A backup for when I do jobs on bass trombone. I use a Holton 1.5G mouthpiece.
I bought this instrument as a 'fixer upper' from eBay. It took quite a lot of work to get it playable!
This came with the Bb sousaphone, and I fit the bell from the other instrument to play it. I use this when I need a lighter brass bass.
Similar to the Stagg Electric Upright Bass, I use this with a re-bodied 120W Hartke bass amp. I have fitted La Bella nylon tape wound double bass strings.
A small student tuba, very light and portable (weighs less than a Sovereign Euphonium!), mostly now replaced with the sousaphones at gigs.
Bought as a restoration project, dates from about 1911. I have a modified Vincent Bach 3 mouthpiece with a small shank which works ok, but I have yet to find something better suited to minimise the stuffiness in the 2nd partial.
More a toy than real instrument, currently in the loft and doesn't get played much. It's awfully flat with a trumpet mouthpiece, but just about ok with a cornet or flugel mouthpiece, and very tricky to get good intonation due to the short slide!